The　convective　heat　transfer　and　the　flow　resistance　in　the　2-D　channel　with　quasi-streamlined　insert　have　been　numerically　studied　in　the　periodically　fully　developed　regime.　The　range　of　the　Reynolds　number　covers　both　the　laminar　and　the　turbulent　flow.　The　effect　of　the　insert　angle,　the　plate　thickness　vs　the　Reynolds　number　on　the　heat　transfer　and　the　friction　factor　has　been　identified.　The　heat　transfer　gets　stronger　monotonically　with　the　insert　angle　from　0　degrees　to　30　degrees.　Nevertheless,　the　insert　angle　impacts　the　flow　resistance　in　the　laminar　case　much　less　than　in　the　turbulent　case.　The　combined　analysis　indicates　that　the　thicker　insert　is　suitable　to　use　in　the　laminar　flow　and　the　thinner　insert　suitable　to　the　turbulent　flow.　In　any　case,　the　quasi-streamlined　insert　acts　as　an　upgrader　to　the　local　heat　transfer　coefficient.　In　comparison　with　the　effect　of　the　original　straight　flow-inclining　insert,　the　streamlined　insert　largely　diminishes　the　flow　resistance　but　with　only　moderate　deterioration　of　the　heat　transfer.　The　assessment　under　the　identical　pump　power　consumption　reveals　the　superiority　of　the　improved　streamline　insert　to　the　straight　one.　(C)　2009　Elsevier　Masson　SAS.　All　rights　reserved.